1. Field of the Invention
The invention generally relates to microwave backhaul architecture, and more specifically to a microwave backhaul architecture supporting a double capacity link.
2. Related Art
Conventional microwave backhaul architectures are generally implemented as either a split outdoor unit (split ODU) configuration or an all outdoor unit (all ODU) configuration. Conventional split ODU configurations are generally comprised of both an indoor unit (IDU) and an outdoor unit (ODU), where the IDU and the ODU are connected over a single channel coaxial interconnect. The IDU in a conventional split ODU configuration typically includes a modem, a digital-to-analog converter and a baseband-to-intermediate frequency converter. Under normal operation, these conventional split ODU configurations generally involve transmitting an analog signal, at an intermediate frequency, over the single channel coaxial interconnect between the IDU and the ODU. However, during this transmission, the analog signal can be subjected to various errors, which can result from deficiencies associated with the IDU. Additionally, the lack of digital capabilities of these conventional ODUs generally render them ineffective in terms of correcting the errors within the analog signal.
Moreover, the ODU implemented within these convention split ODU configurations are generally only capable of transmitting a single channel over a wireless link. In particular, transmitting more than one channel through a conventional ODU and over the wireless link typically causes difficulties from a linearity perspective. For example, cross modulation products from the multiple channels generally will not meet noise floor European Telecommunications Standards Institute (ETSI) standards. Consequently, these conventional split ODU configurations are further rendered inefficient because they are only capable of supporting a single channel wireless link having a relatively low capacity. Therefore, as the demand for higher capacity mobile backhaul networks continues to increase, the limitations associated with these conventional split ODU configurations will only become more problematic.
In particular, mobile backhaul providers are experiencing a growing demand for increased capacity as well as a shift from voice services to data services. These Factors are driving mobile backhaul networks towards high capacity IP/Ethernet connections. Additionally, the transition to 4G and LTE networks is also driving the need for higher capacity, and moving more packet traffic onto mobile backhaul networks. As a result, the limitations of conventional split ODU configurations, which only support a single channel (relatively low capacity) link, make it increasingly difficult to meet these increasing user demands.
In some instances, all ODU configurations have been used as an alternative to these conventional split ODU configurations. Conventional all ODU configurations include only an ODU, and thus do not include an IDU. The ODU therefore includes a modem, a digital-to-analog converter as well as a baseband-to-radio frequency converter. Implementing all of these functional components in the ODU typically provides some digital capabilities within the ODU, and also typically allows for the implementation of digital connectivity within these conventional all ODU configurations. This is in contrast to the typical ODU utilized in the conventional split ODU configuration, which, generally lacks digital capabilities, and generally utilizes analog connectivity. However, the conventional all ODU configurations are also subject to the limitations described above. For example, conventional all ODU configurations are still generally only capable of transmitting a single channel over the wireless link. Consequently, similar to the conventional split ODU configurations, these conventional all ODU configurations are also rendered inefficient because they are only capable of supporting a single channel wireless link, which results in the wireless link having a relatively low capacity.
Thus, neither conventional split ODU configurations nor all ODU configurations effectively meet the increasing demands for capacity.
Embodiments of the disclosure will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the reference number